The invention relates to powering computer systems. In particular, the invention relates to providing a computer system with a reliable power supply for use in environments and applications that place high demands on system reliability, for example in the telecommunications industry.
Deregulation and privatization is causing unprecedented competition in the worldwide telecommunications market. This climate of fierce competition has meant that service providers must introduce new, more sophisticated and user-friendly services at an accelerated pace to retain or attract subscribers, while not compromising traditional telecommunications company (telco) service quality.
These pressures of competition have also placed high demands on Network Equipment Providers (NEPs). Traditionally, NEPs have designed, built and supported proprietary computing equipment, as the strict telco requirements could not be met by the commercial computing sector. Those requirements include the so-called Telcordia Technologies Network Equipment Buildings Systems (NEBS) tests. However, due to the lead times required to design and test such proprietary equipment, and the cost of supporting such equipment, there is a need to find another route, at least for the supply of the more cost and performance sensitive sectors within the telco industry.
A major concern of the telco sector is the reliability of systems. To address this issue, many prior systems, for example for providing the function of a telco server computer, have employed redundancy in computer systems. For example, it is known to provide redundancy in power supplies. However, it is desirable to provide for hot swappability of the redundant power supplies (n+m power supplies). It would also be desirable to provide adaptability to accommodate different earthing requirements.
Accordingly, it is an aim of the present invention to address the provision of cost-effective equipment that can meet technical demands of the telco environments as described above, while also meeting the modern commercial demands of that environment.
Particular and preferred aspects of the invention are set out in the accompanying independent and dependent claims. Combinations of features from the dependent claims may be combined with features of the independent claims as appropriate and not merely as explicitly set out in the claims.
In accordance with an aspect of the invention, there is provided a power supply unit removably mountable in electronic equipment. The power supply unit includes a metal chassis, an external chassis grounding connection for grounding the metal chassis and an external logic grounding connection for logic ground. The external logic grounding connection is electrically insulated from the metal chassis. A grounding plate is configured to be externally mounted in a removable manner between the external chassis grounding connection and the external logic grounding connection.
The use of power supply units with an externally mounted grounding plate provides a flexible and user friendly way of selectively connecting or isolating logic ground from chassis ground. This is particularly advantageous in telecommunications system where different installations will have different grounding requirements.
Where plural power supply units are provided in a redundant xe2x80x9cn+1xe2x80x9d configuration, or the like, hot swappability can be provided in both connected and isolated logic ground configurations. When it is desired to isolate the electrical and chassis grounds, then each of the grounding plates are removed.
The chassis grounding connection can be formed by a single metal stud, which can also be self-retained in the power supply chassis. This means that the connection of the grounding plate can readily be achieved simply using a nut that engages over the threaded stud. Similarly, the logic grounding connection can be formed by a pair of metal studs, that can each be self-retained in the power supply chassis. This means that the connection of the grounding plate can readily be achieved simply using a pair of nuts that engages over a respective one of the threaded studs. The studs for mounting the grounding plate can be on a rear surface of the power supply unit so as to be readily accessible.
In accordance with another aspect of the invention, there is provided a power sub-system for electronic equipment, the power sub-system comprising a plurality of removable power supply units, and a power distribution mechanism to which the power supply units are connectable, each of the power supply units comprising a metal chassis, an external chassis grounding connection for grounding the metal chassis and an external logic grounding connection for logic ground, the external logic grounding connection for logic ground being electrically insulated from the metal chassis, and a grounding plate configured to be externally mounted in a removable manner between the external chassis grounding connection and the external logic grounding connection.
In accordance with a further aspect of the invention, there is provided a system unit comprising a metal system chassis, an external system chassis grounding connection, electronic circuitry, a plurality of removable power supply units, and a power distribution mechanism to which the power supply units are connectable, each of the power supply units comprising a metal power supply chassis, an external power supply chassis grounding connection for grounding the power supply metal chassis and an external logic grounding connection for logic ground, the external logic grounding connection for logic ground being electrically insulated from the power supply metal chassis, and a grounding plate configured to be externally mounted in a removable manner between the external power supply chassis grounding connection and the external logic grounding connection.
In an embodiment of the invention, there are three power supply units, where two power supply units are needed to power the system unit. The use of a power supply system with three power supply units, where two power supplies are needed to power the system, means that the system can still operate if one of the power supply units fails. As each power supply unit only needs to be of a capacity half of that required to power the computer system, the size and cost of providing a redundant power supply sub-system can be kept down.
In an embodiment of the invention, the system unit includes a sub-frame for removably receiving the power supply units. The sub-frame is located at a rear of the system unit. The system chassis grounding connection comprises a pair of metal studs. The system unit is mountable within a rack system and comprising a computer system including a processor and memory.
In accordance with yet another aspect of the invention, there is provided a method of powering a system unit comprising a metal system chassis, an external system chassis grounding connection, electronic circuitry, a plurality of removable power supply units, and a power distribution mechanism to which the power supply units are connectable, each of the power supply units comprising a metal power supply chassis, an external power supply chassis grounding connection for grounding the power supply metal chassis and an external logic grounding connection for logic ground, the external logic grounding connection for logic ground being electrically insulated from the power supply metal chassis, the method comprising the external mounting in a removable manner of a grounding plate between the external power supply chassis grounding connection and the external logic grounding connection of at least one power supply unit to connect logic and chassis ground.